From: Kees Cook <keescook@chromium.org>
To: alex.popov@linux.com, Dave Hansen <dave.hansen@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
Laura Abbott <labbott@redhat.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Andy Lutomirski <luto@kernel.org>,
PaX Team <pageexec@freemail.hu>,
Brad Spengler <spender@grsecurity.net>,
Ingo Molnar <mingo@kernel.org>, Tycho Andersen <tycho@tycho.ws>,
Mark Rutland <mark.rutland@arm.com>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Borislav Petkov <bp@alien8.de>,
Richard Sandiford <richard.sandiford@arm.com>,
Thomas Gleixner <tglx@linutronix.de>,
"H . Peter Anvin" <hpa@zytor.com>,
"Dmitry V . Levin" <ldv@altlinux.org>,
Emese Revfy <re.emese@gmail.com>,
Jonathan Corbet <corbet@lwn.net>,
Andrey Ryabinin <aryabinin@virtuozzo.com>,
"Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
Thomas Garnier <thgarnie@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
Alexei Starovoitov <ast@kernel.org>, Josef Bacik <jbacik@fb.com>,
Masami Hiramatsu <mhiramat@kernel.org>,
Nicholas Piggin <npiggin@gmail.com>,
Al Viro <viro@zeniv.linux.org.uk>,
"David S . Miller" <davem@davemloft.net>,
Ding Tianhong <dingtianhong@huawei.com>,
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Steven Rostedt <rostedt@goodmis.org>,
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Juergen Gross <jgross@suse.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Dan Williams <dan.j.williams@intel.com>,
Mathias Krause <minipli@googlemail.com>,
Vikas Shivappa <vikas.shivappa@linux.intel.com>,
Kyle Huey <me@kylehuey.com>,
Dmitry Safonov <dsafonov@virtuozzo.com>,
Will Deacon <will.deacon@arm.com>, Arnd Bergmann <arnd@arndb.de>,
x86@kernel.org, linux-kernel@vger.kernel.org,
"kernel-hardening@lists.openwall.com"
<kernel-hardening@lists.openwall.com>
Subject: Re: [PATCH RFC v9 2/7] x86/entry: Add STACKLEAK erasing the kernel stack at the end of syscalls
Date: Mon, 26 Mar 2018 10:32:04 -0700 [thread overview]
Message-ID: <CAGXu5jKLErrvewvSiusr7qPup-08YgvLKC1ZT7FKTR_RyDSTuQ@mail.gmail.com> (raw)
In-Reply-To: <ac1a2090-e120-d202-35b4-b158d4787ab5@linux.com>
On Thu, Mar 22, 2018 at 1:56 PM, Alexander Popov <alex.popov@linux.com> wrote:
> By the way, during my work on STACKLEAK, I've found one case when we get to the
> userspace directly from the thread stack. Please see sysret32_from_system_call
> in entry_64_compat.S. I checked that.
>
> IMO it seems odd, can the adversary use that to bypass PTI?
If it was missing the page table swap, shouldn't this mean that the
missing NX bit would immediately crash userspace?
-Kees
--
Kees Cook
Pixel Security
next prev parent reply other threads:[~2018-03-26 17:32 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-03 20:00 [PATCH RFC v9 0/7] Introduce the STACKLEAK feature and a test for it Alexander Popov
2018-03-03 20:00 ` [PATCH RFC v9 1/7] gcc-plugins: Clean up the cgraph_create_edge* macros Alexander Popov
2018-03-03 20:00 ` [PATCH RFC v9 2/7] x86/entry: Add STACKLEAK erasing the kernel stack at the end of syscalls Alexander Popov
2018-03-05 16:41 ` Dave Hansen
2018-03-05 19:43 ` Laura Abbott
2018-03-05 19:50 ` Dave Hansen
2018-03-05 20:25 ` Peter Zijlstra
2018-03-05 21:21 ` Alexander Popov
2018-03-05 21:36 ` Kees Cook
2018-03-21 11:04 ` Alexander Popov
2018-03-21 15:33 ` Dave Hansen
2018-03-22 20:56 ` Alexander Popov
2018-03-26 17:32 ` Kees Cook [this message]
2018-03-26 17:43 ` Andy Lutomirski
2018-03-03 20:00 ` [PATCH RFC v9 3/7] gcc-plugins: Add STACKLEAK plugin for tracking the kernel stack Alexander Popov
2018-03-03 20:00 ` [PATCH RFC v9 4/7] x86/entry: Erase kernel stack in syscall_trace_enter() Alexander Popov
2018-03-05 19:40 ` Dave Hansen
2018-03-05 20:06 ` Kees Cook
2018-03-05 20:15 ` Linus Torvalds
2018-03-05 21:02 ` Alexander Popov
2018-03-05 21:02 ` Kees Cook
2018-03-05 21:40 ` Linus Torvalds
2018-03-05 22:07 ` Linus Torvalds
2018-03-06 0:56 ` Kees Cook
2018-03-06 4:30 ` Linus Torvalds
2018-03-06 17:58 ` Andy Lutomirski
2018-03-06 7:56 ` [OLD PATCH] net: recvmsg: Unconditionally zero struct sockaddr_storage " Ingo Molnar
2018-03-06 8:08 ` Ingo Molnar
2018-03-06 15:16 ` Daniel Micay
2018-03-06 15:28 ` Daniel Micay
2018-03-06 18:56 ` Linus Torvalds
2018-03-06 19:07 ` Peter Zijlstra
2018-03-06 19:07 ` Ard Biesheuvel
2018-03-06 19:16 ` Linus Torvalds
2018-03-06 20:42 ` Arnd Bergmann
2018-03-06 21:01 ` Linus Torvalds
2018-03-06 21:21 ` Arnd Bergmann
2018-03-06 21:29 ` Linus Torvalds
2018-03-06 22:09 ` Arnd Bergmann
2018-03-06 22:24 ` Linus Torvalds
2018-03-06 21:36 ` Steven Rostedt
2018-03-06 21:41 ` Linus Torvalds
2018-03-06 21:47 ` Linus Torvalds
2018-03-06 22:29 ` Steven Rostedt
2018-03-06 22:41 ` Linus Torvalds
2018-03-06 22:52 ` Steven Rostedt
2018-03-06 23:09 ` Linus Torvalds
2018-03-12 8:22 ` Ingo Molnar
2018-03-12 9:00 ` Ard Biesheuvel
2018-03-12 9:21 ` Ingo Molnar
2018-03-06 21:47 ` Arnd Bergmann
2018-03-06 22:19 ` Linus Torvalds
2018-03-05 20:26 ` Peter Zijlstra
2018-03-03 20:00 ` [PATCH RFC v9 5/7] lkdtm: Add a test for STACKLEAK Alexander Popov
2018-03-03 20:00 ` [PATCH RFC v9 6/7] fs/proc: Show STACKLEAK metrics in the /proc file system Alexander Popov
2018-03-03 20:00 ` [PATCH RFC v9 7/7] doc: self-protection: Add information about STACKLEAK feature Alexander Popov
2018-03-05 19:34 ` [PATCH RFC v9 0/7] Introduce the STACKLEAK feature and a test for it Kees Cook
2018-03-05 19:42 ` Dave Hansen
2018-03-05 20:02 ` Kees Cook
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